Laminated floor covering

ABSTRACT

There is disclosed herein various floor coverings and methods for making the same. In one embodiment, there is disclosed a floor covering including a primary backing layer having a fibrous face and an underside, wherein the fibrous face is formed from a bulked continuous filament yam comprising a plurality of continuous filaments formed from a biobased polyhexamethylene sebacamide polymer or a blend of a biobased polyhexamethylene sebacamide polymer together with up to 80 wt % of at least one other polymer compatible with the biobased polyhexamethylene sebacamide polymer. There is also described a method of making a floor covering comprising: tufting or implanting a bulked continuous filament yarn into a primary backing material, wherein the yam comprises a plurality of continuous filaments formed from a multi-component fibre comprising a biobased polyhexamethylene sebacamide polymer or a blend of a biobased polyhexamethylene sebacamide polymer together with up to 80 wt % of at least one other polymer compatible with the biobased polyhexamethylene sebacamide polymer.

TECHNICAL FIELD

The present invention relates to a laminated floor covering such as acarpet or carpet tile and to a method for making the laminated floorcovering.

BACKGROUND OF THE INVENTION

Carpets, such as free-lay carpet or backed carpet tiles are typicallyprepared as either a tufted or a fusion bonded carpet material having awear fibrous or pile surface from which pile yarns upwardly project.Carpet tiles differ from the production of ordinary tufted or otherfibrous-faced carpets because there is no requirement on a typicalcarpet for a heavy backing layer. In a carpet tile, a rigid stabilizedmass of a thermoplastic backing layer is required in order to hold downthe carpet tile so that it can function as a free-lay carpet tile.Generally, the backing layer has a high filler content (e.g., limestone)and is employed with various scrim materials such as glass fibres,polyester or a combinations thereof, to impart dimensional stability.Generally the thermoplastic backing layer is one or more polyvinylchloride layers.

As an example, a tufted carpet tile generally comprises a primarybacking base sheet material such as polyester or polypropylene having aplurality of tufted yarns such as Nylon® through the primary backing toform a wear surface of loop or cut pile (carpet pile). The primarybacking is used to tuft the carpet yarn into and to provide the requiredtop cloth of the product. A precoat of a latex type material such as EVA(polyethylene vinyl acetate) or carboxylated styrene-butadiene-styrenemay be applied on the back (underside) surface to bond the yarn to theprimary backing and to aid in the securing of the primary backing to thebacking layer. The backing layer may be comprised of a first PVC layer,a fiberglass layer and a second PVC layer (reback layer)—the first layerof PVC bonding the primary backing to the fiberglass layer, thefiberglass layer ensuring dimensional stability of the carpet tile andthe second layer of PVC gluing the layers above it and providing thefinal backing of the carpet tile.

In an alternative construction of the above carpet tiles, the PVC layeris replaced with a bitumen layer.

Fusion-bonded carpet generally has a similar backing to tufted carpetexcept that the fusion-bonded carpet has a plurality of cut pile yarnsof nylon or other suitable fibrous material implanted in an adhesivelayer, particularly thermoplastic such as PVC or hot-melt adhesive,which may be further laminated to a reinforcement or substrate layer ofa woven or non-woven material such as fibreglass, Nylon®, polypropyleneor polyester. The plurality of fibrous yarns are bonded to and extendgenerally upright from the adhesive base layer to form the wear surface.

The above constructions suffer from the disadvantages that the carpetand carpet tiles are made from environmentally unfriendly materials. Forexample Nylon® use in the fibrous or pile surface is made from oil andis a non-renewable resource.

It would be desirable to provide a carpet or carpet tile which is formedfrom more environmentally friendly materials.

OBJECT OF THE INVENTION

It is an object of the present invention to substantially overcome or atleast ameliorate one or more of the above disadvantages or at leastprovide a suitable alternative.

DEFINITIONS

The following are some definitions that may be helpful in understandingthe description of the present invention: These are intended as generaldefinitions and should in no way limit the scope of the presentinvention to those terms alone, but are put forth for a betterunderstanding of the following description.

Unless the context requires otherwise or specifically stated to thecontrary, integers, steps, or elements of the invention recited hereinas singular integers, steps or elements clearly encompass both singularand plural forms of the recited integers, steps or elements.

Throughout this specification, unless the context requires otherwise,the word “comprise”, or variations such as “comprises” or “comprising”,will be understood to imply the inclusion of a stated step or element orinteger or group of steps or elements or integers, but not the exclusionof any other step or element or integer or group of elements orintegers. Thus, in the context of this specification, the term“comprising” means “including principally, but not necessarily solely”.

The information provided herein and references cited are provided solelyto assist the understanding of the reader, and do not constitute anadmission that any of the references or information is prior art to thepresent invention.

The term “filament” or “filaments” means strands of extreme orindefinite length. The term “yarn” means a collection of numerousfilaments which may or may not be entangled, twisted or laid together.

The term “texturing” means any operation of filaments which results incrimping, looping or otherwise modifying such filaments to increasecover, resilience, bulk or to provide a different surface texture orhand. It follows that a “bulked continuous filament” is a filament whichhas been subjected to one or more “texturing” operation(s).

By “biobased” is meant that the relevant material is made fromsubstances derived from living matter.

A biobased fibre is herein defined as a fibre comprised of a polymer, ora blend or alloy of two or more polymers, in which one or more of saidpolymers has as at least one of the components making up themacromolecule thereof a substance ultimately derived wholly or partiallyfrom a biological, renewable, source. Such source may, for example, be aplant, or part of said plant such as roots, stems, leaves, flowers orseeds.

It will be understood that although the description of the carpet orcarpet tile of the present invention has been given in terms of“layers”, that following processing the carpet tile is a bonded unitaryintegral structure in which the individual layers are not necessarilyreadily discernible or removable from one another.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is provideda floor covering including a primary backing layer having a fibrous faceand an underside, wherein the fibrous face is formed from a bulkedcontinuous filament yarn comprising a plurality of continuous filamentsformed from a biobased polyhexamethylene sebacamide polymer or a blendof a biobased polyhexamethylene sebacamide polymer together with up to80 wt % of at least one other polymer compatible with the biobasedpolyhexamethylene sebacamide polymer.

According to second aspect of the present invention, there is provided amethod of making a floor covering comprising

tufting or implanting a bulked continuous filament yarn into a primarybacking material, wherein the yarn comprises a plurality of continuousfilaments formed from a multi-component fibre comprising a biobasedpolyhexamethylene sebacamide polymer or a blend of a biobasedpolyhexamethylene sebacamide polymer together with up to 80 wt % of atleast one other polymer compatible with the biobased polyhexamethylenesebacamide polymer.

According to a third aspect of the present invention there is provided afloor covering comprising:

a primary backing having a fibrous face and an underside, wherein thefibrous face is formed from a bulked continuous filament yarn comprisinga plurality of continuous filaments formed from a biobasedpolyhexamethylene sebacamide polymer or a blend of a biobasedpolyhexamethylene sebacamide polymer together with up to 80 wt % of atleast one other polymer compatible with the biobased polyhexamethylenesebacamide polymer;

a cured precoat layer on the underside of the primary backing, and abacking layer fixed to the primary backing.

According to a fourth aspect of the present invention, there is provideda method of making a floor covering comprising:

tufting or implanting a bulked continuous filament yarn into a primarybacking, wherein the yarn comprises a plurality of continuous filamentsformed from a multi-component fibre comprising a biobasedpolyhexamethylene sebacamide polymer or a blend of a biobasedpolyhexamethylene sebacamide polymer together with up to 80 wt % of atleast one other polymer compatible with the biobased polyhexamethylenesebacamide polymer;

precoating the underside of the primary backing layer by applying aprecoating composition, applying a backing layer to the precoatedprimary backing layer, and

curing the precoating composition.

According to a fifth aspect of the present invention, there is provideda method of making a floor covering comprising:

coating a first layer of a thermoplastic resin plastisol on a supportsurface

optionally placing a dimensionally stable sheet material onto the topsurface of the first layer and heating the layer to gel the layer andposition the sheet material

optionally applying a second layer of a thermoplastic resin plastisolonto the gelled surface of the first layer;

tufting or implanting a bulked continuous filament yarn into a primarybacking material, wherein the yarn comprises a plurality of continuousfilaments formed from a multi-component fibre comprising a biobasedpolyhexamethylene sebacamide polymer or a blend of a biobasedpolyhexamethylene sebacamide polymer together with up to 80 wt % of atleast one other polymer compatible with the biobased polyhexamethylenesebacamide polymer,

precoating the underside of the primary backing;

optionally coating a thermoplastic resin plastisol over the precoatlayer;

layering the precoated primary backing onto the top surface of theplastisol of the first or second thermoplastic resin layer,

heating the floor covering so formed to fuse the thermoplastic layersinto an integrally-fused backing layer,

cooling the flooring covering, and

optionally cutting the floor covering into a carpet tile.

According to a sixth aspect of the invention, there is provided a floorcovering produced by the method of the fifth aspect.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to a floor covering including a primarybacking layer having a fibrous face and an underside, wherein thefibrous face is formed from a bulked continuous filament yarn comprisinga plurality of continuous filaments formed from a biobasedpolyhexamethylene sebacamide polymer or a blend of a biobasedpolyhexamethylene sebacamide polymer together with up to 80 wt % of atleast one other polymer compatible with the biobased polyhexamethylenesebacamide polymer.

The present invention also relates to a method of making a floorcovering comprising tufting or implanting a bulked continuous filamentyarn into a primary backing material, wherein the yarn comprises aplurality of continuous filaments formed from a multi-component fibrecomprising a biobased polyhexamethylene sebacamide polymer or a blend ofa biobased polyhexamethylene sebacamide polymer together with up to 80wt % of at least one other polymer compatible with the biobasedpolyhexamethylene sebacamide polymer.

There is also provided a floor covering comprising:

a primary backing having a fibrous face and an underside, wherein thefibrous face is formed from a bulked continuous filament yarn comprisinga plurality of continuous filaments formed from a a biobasedpolyhexamethylene sebacamide polymer or a blend of a biobasedpolyhexamethylene sebacamide polymer together with up to 80 wt % of atleast one other polymer compatible with the biobased polyhexamethylenesebacamide polymer;

a cured precoat layer on the underside of the primary backing,

and a backing layer fixed to the primary backing.

There is also provided a method of making a floor covering comprising:

tufting or implanting a bulked continuous filament yarn into a primarybacking, wherein the yarn comprises a plurality of continuous filamentsformed from a multi-component fibre comprising a biobasedpolyhexamethylene sebacamide polymer or a blend of a biobasedpolyhexamethylene sebacamide polymer together with up to 80 wt % of atleast one other polymer compatible with the biobased polyhexamethylenesebacamide polymer;

precoating the underside of the primary backing layer by applying aprecoating composition,

applying a backing layer to the precoated primary backing layer, and

curing the precoating composition.

There is also provided a method of making a floor covering comprising:

coating a first layer of a thermoplastic resin plastisol on a supportsurface

optionally placing a dimensionally stable sheet material onto the topsurface of the first layer and heating the layer to gel the layer andposition the sheet material

optionally applying a second layer of a thermoplastic resin plastisolonto the gelled surface of the first layer;

tufting or implanting a bulked continuous filament yarn into a primarybacking material, wherein the yarn comprises a plurality of continuousfilaments formed from a mufti-component fibre comprising a biobasedpolyhexamethylene sebacamide polymer or a blend of a biobasedpolyhexamethylene sebacamide polymer together with up to 80 wt % of atleast one other polymer compatible with the biobased polyhexamethylenesebacamide polymer,

precoating the underside of the primary backing;

optionally coating a thermoplastic resin plastisol over the precoatlayer;

layering the precoated primary backing onto the top surface of theplastisol of the first or second thermoplastic resin layer,

heating the floor covering so formed to fuse the thermoplastic layersinto an integrally-fused backing layer,

cooling the flooring covering, and

optionally cutting the floor covering into a carpet tile.

There is also provided a floor covering produced by the methods.

Yarn

The biobased polyhexamethylene sebacamide polymer is suitably UltramidBalance 6,10 available from BASF. This material is a polyamide 6,10based on over 60% on sebacic acid derived from castor oil, which isitself a renewable resource obtained from the seeds of Ricinus Communis.Suitably the polymer is 63% biobased. In one embodiment the biobasedpolyhexamethylene sebacamide polymer is blended with up to 80 wt % of atleast one polymer compatible with the biobased polyhexamethylenesebacamide polymer. Suitable polymers for blending with the biobasedpolyhexamethylene sebacamide polymer include, but are not limited tonylon 6,6 or nylon 6,12.

The biobased polyhexamethylene sebacamide bulked continuous filament(BCF) yarn may be prepared by melt-spinning a polymer melt containingpolyhexamethylene sebacamide polymer or a blend of a biobasedpolyhexamethylene sebacamide polymer together with up to 80 wt % of atleast one other polymer compatible with the biobased polyhexamethylenesebacamide polymer to form at least one filament, passing the at leastone filament to a drawing stage where the filament is drawn andlengthened, followed by texturing.

In one embodiment the process is conducted continuously. In anotherembodiment, the process is conducted as independent sequentialoperations.

Suitably the polymer melt may have a colourant dispersed therein priorto spinning, the colourant selected from at least one pigment and/orpolymer soluble dyestuff. Alternatively, the resulting spun filaments,drawn filaments or bulked continuous yarn may be dyed. The at least onedispersed colourant may be any suitable pigment and may be chosen fromorganic and/or inorganic classes. In one embodiment the pigment is atleast one pigment chosen from among: quinacridone magenta PR202,perylene red PR178, iron oxide red PR101, zinc iron yellow PY119, nickelazo yellow PY150, phthalocyanine green PG7, phthalocyanine blue PB15:1,titanium dioxide PW6 and carbon black PBlk7. The range of colourant tobe added is typically bounded by a functional minimum below whichappearance or lightfastness is unsuitable or a functional maximum atwhich chromatic saturation is achieved. While different for each of theaforenamed inorganic and organic colourants, a typical minimum of 0.05wt % and a typical maximum of 2.5 wt % may be encountered.

Suitably the polymer melt includes at least one stabiliser. In thisregard, the stabiliser may be any suitable stabiliser. In one embodimentthe stabiliser is a mixture of cuprous iodide, potassium iodide andpotassium bromide or other suitable stabiliser. Other suitablestabilisers included members of the benzatriazole or hindered aminefamilies. In one embodiment cuprous cation may be included in a rangebetween 10 and 100 ppm. In another embodiment halide anion may beincluded in the range between 100 and 5000 ppm. In another embodimentbenzatriazole or hindered amines may be included in the range of 0.1 to2.0 wt %.

Other optional additives which may be added to the polymeric meltinclude, but are not limited to, one or more of antistatics,antioxidants, antimicrobials, flameproofing agents, delustering agents,and lubricants.

Any or all of the above colourants, stabilisers and additives may beincorporated into the polymer melt by direct metering. Any or all of theabove colourants, stabilisers and additives may be incorporated into thepolymer melt in the form of a masterbatch, which term is well know tothose skilled in the art. The carrier resin for use in the masterbatchis preferably the same polymer as that forming the continuous filamentsbut may also be any fibre-forming polymer fully miscible with thebiobased polyhexamethylene sebacamide. Resins such as functionallymodified polyesters and functionally modified or unmodified polyamidessuch as Nylon 6,6 and Nylon 6, 12 may also be used as carrier resin.Suitably, the colourants and/or stabilisers and/or additives arecompounded into the carrier so that they are suitably dispersed. Thecolourants and/or stabilisers and/or additives and the preparedmasterbatch are suitably dried to a moisture content of less than 0.2 wt%.

The speed and temperature of the process is suitably chosen to optimisethe physical properties of the formed fibre whilst maximising throughputeconomics.

Suitably the spin speed of the polymeric melt is about 400 m/min-1500m/min, for example about 1100 m/min. In one embodiment an extrudersupplies molten polymeric material to a spinning head, the spinning headincluding spinnerettes having multiple small orifices through which themolten polymer material is extruded to form filaments which are thensuitably passed to a quench chamber where a quench gas (such as air,steam or an inert gas such as nitrogen) is provided to cool and solidifythe filaments. Suitably the quench gas is directed at the filament in adirection perpendicular to the filament travel.

Suitably the filaments are converged into a multifilament yarn prior topassing the yarn through the drawing stage. Suitably drawing is eitherover a contact point or around a roll. In this regard typically drawingis conducted on separated pairs of godet rolls or pairs (duos) operatingat different rotational speeds. The filament(s) are drawn between therolls at a desired draw ratio dependent on the speed differential, yarntemperature and yarn speed. The rolls are suitably heated to the same orsimilar temperature to elevate the filament temperature prior totexturing. In one embodiment the fibre is subjected to orientationthrough drawing and by allowing for crystalline growth and morphologicalalignment for example by allowing the fibre to dwell in repetitivetransitory residence across at least one roller which mayanisotropically orient the molecules in the filament thereby improvinglateral strength.

Suitably the draw ratio is 2:1 to 4:1, more preferably the draw ratio isapproximately 3 or below. Suitably, the filament is passed into thedrawing stage at a speed of 1500 m/min or less, exiting at the describedmultiple speed thereof, whereby texturing may be practicallyaccomplished. Suitably the texturing is conducted by means of a fluidjet texturing unit and the filament is fed into the unit at a ratefaster than the rate at which the textured yarn is drawn off.Alternatively the texturing is conducted by means of mechanicalcrimping. Suitably the texturing increases the bulk of the fibre. Thetexturing imparted is suitably sufficient to induce dry heat shrinkagein excess of the linear shrinkage solely induced by orientation.Following texturing the yarn may be allowed to equilibrate naturally orin an accelerated manner by applying a moist heat environment.

At some suitable stage during the aforementioned processes, yarn isbrought into contact with a finish applicator whereby a liquid finish isapplied as desired. The finish may be applied at a single point or inmultiple stages.

The textured or textured and finished yarn may be suitably combined withother yarns of the same or different type to form larger assembliesthrough air entanglement of multiple colours (such as on a Gilbos unitor one of suitable design) or through cable twisting, air twisting orbraiding to form a finished yarn of the required design and aestheticrequirements.

The textured or textured and finished yarn may then be wound onto apackage.

The above process steps may be conducted in a continuous sequence or maybe conducted separately. Preferably the process steps are conducted inan uninterrupted sequence.

Typically, but without limitation; each yarn will have a denier of 15 to21, a tenacity of 2.5 to 3.5 grams/denier and an elongation to break ofgreater than 30%. Denier is defined as the number of grams in 9,000 mlength.

Primary Backing Layer

The primary backing may be a tufted fibrous layer or a fusion bondedmaterial. When a tufted fibrous layer is used, it may be prepared byfeeding the primary backing material to a conventional tufting machinewhich tufts fibres through interstices in the material. Tufting istypically performed such the resulting tufts protrude from the undersideface with back stitches which hold the tufts in place on the topside ofthe material during processing

The primary backing is suitably formed from a woven or non-wovensynthetic or non-synthetic fibre. Suitably a thermoplastic backing suchas a woven polypropylene backing or a non-woven polyester, with afibrous face or wear surface such as a tufted face, and a fibrous backsurface, such as a loop or tufted surface where the carpet tile istufted is used. A polyester such as Lutradur® is preferably used whenmaking a PVC backed floor covering because it does not suffer too muchfrom shrinkage due to heat during the gelling process thus minimizingthe risk of tile uplift due to not enough drape. Other suitable backingsinclude Nylon®, fibreglass, cotton, jute, rayon, paper, natural orsynthetic rubbers, sponge or foam rubbers, polychloroprene,acrylonitrile-butadiene copolymers, ethylene-propylene-diene rubbers,petroleum resin, vinyl polymers (such as polyvinylchloride,polyvinylidene chloride, polyvinyl acetate, polyvinyl acetal, polyvinylbutyral, copolymers or mixtures thereof), polybutene resin,polyisobutene-butadiene resins and copolymers and mixtures thereof.

The yarn may be used together with other fibrous materials and yarnsemployed in the floor coverings. Such fibrous materials and yarns mayinclude synthetic, natural or a combination of synthetic and naturalfibre, such as but not limited to other polyamides like nylon, olefinslike polypropylene, wool and wool blends, cotton, acrylic, acrylic-nylonblends, polyester yarns and combinations and blends thereof. Theyarns/fibrous materials may be used to form face or back yarn with theprimary backing.

For a fusion bonded carpet tile, the fibrous material and yarns employedin the carpet tile are implanted into a material such as PVC or a hotmelt adhesive which may be laminated to a substrate such as a woven ornonwoven material such as fibreglass, Nylon®, polypropylene orpolyester.

The primary backing layer may be precoated with Latex or with anothersuitable precoating composition of the invention prior to applying abacking layer. Typically the precast is applied to cover the loop backsand to lock in the loops.

Latex

The latex may be an EVA latex or another vinyl polymer or acrylic-likepolymer latex. For example, the latex may be a copolymer of acrylic andmethacrylic acid and alkyl acrylates and esters (such as ethyl acrylateor methyl acrylate), acrylic-styrene copolymers, acrylonitrile-styrenecopolymers, vinylidene chloride-acrylonitrile copolymers, andcombinations thereof. Suitably the latex is non-halogenated. Othersuitable latex materials which can be use include other vinyl,short-chain carboxylic acid copolymers, butadiene-acrylonitrilecopolymer, styrene-butadiene, carboxylated styrene-butadiene,carboxylated styrene-butadiene-styrene. Urethane, PVC, acrylics orvinylidine chloride may also be used.

The precoating composition/latex may further comprise a thickener, anantibacterial, a fire retardant and/or a surfactant. A suitableantibacterial is zinc omadine—zinc2-pyridinethiol-1-oxide. A suitablefire retardant is aluminium hydroxide. A suitable surfactant is sodiumlauryl sulphate.

In one embodiment a precoating composition is used comprising: at leastone copolymer derived from an acrylic or methacrylic monomer and astyrenic monomer; at least one copolymer derived from an acrylic esterand a methacrylic ester, at least one thickener; and water. Thecopolymer derived from an acrylic or methacrylic monomer and a styrenicmonomer is suitably an acrylate/styrene copolymer dispersion such asthat supplied by BASF Corporation as Acronal® S 728 na. Acronal® S 728na is a butyl acrylate/styrene copolymer dispersion and contains waterin an amount of 49 to 51% w/w and a proprietory copolymer in an amountof about 49 to 51% w/w. The dispersion has a flash point greater than300° F. (149° C.), a milky white with a faint ester-like odour, a pH ofabout 6.5 to 7.5, a boiling point of 212° C. (760 mmHg), a vapourpressure of 23 mbar (20° C.), a relative density of 1.04 (20° C.), aviscosity of 200 to 700 mPa·s and is miscible in water. This copolymeris traditionally used for coating in the paper industry but to date hasnot been used in the preparation of carpet tiles. Prior to addition tothe precoating composition, the copolymer is suitably diluted to 25%solids with water. As indicated above the precoating composition mayalso contain a copolymer derived from an acrylic ester and a methacrylicester. This copolymer facilitates the acrylic styrene sticking tothermoplastic materials such as PVC suitably used in the manufacture ofthe floor coverings. A suitable polymer is Acronal® AX 8281 AP availablefrom BASF Aktiengesellschaft. This dispersion is white in colour withfaint odour and a pH value of 7 to 8, a density of about 1.02 g/cm³ at20° C., a dynamic viscosity of 300 to 1500 mPa·s (23° C.) and a solidscontent of 48.5 to 51.5%. The polymeric dispersion is miscible in water.This acrylic addition raises the glass temperature in the aqueoussolution. If used alone this acrylic resin is very brittle. Inclusiontogether with the acrylate/styrene copolymer allows the composition tostick/lock to the backing layer. Suitably about 20% dry weight ofAcronal® is added (16% volume). The precoating composition suitablycontains a thickener. Suitably the thickener is a thickener suitable forpolymer dispersions, for example, an acrylic copolymer containingcarboxyl groups. A suitable thickener is Latekoll® D available from BASFAktiengesellschaft and is a low-viscosity, milky white anionicdispersion. Latekoll® D has a solids content (ISO 1625) of about 25±1%,a pH value of 2.3 to 3.3, a viscosity at 23° C., shear rate 250 s⁻¹ of2-10 mPa·s and a density at 20° C. of about 1.05 g/cm³. The thickenerhelps to prevent the precoating composition from wicking down holes inthe primary backing layer. The thickener is suitably pre-diluted withwater to form a homogeneous solution prior to the addition to theresins.

The precoating composition described above can be prepared by firstmixing the copolymer derived from an acrylic or methacrylic monomer anda styrenic monomer and the copolymer derived from an acrylic ester and amethacrylic ester followed by addition of the thickener which has beenpre-diluted with water, followed by addition of additional water. About20% (of the dry weight of S728) of the AX8281 Acronal® is suitably addedto the Acronal® S728 and suitably 1 to 2 wt % (up to 5%) of thickeneradded. It is important not to add too much thickener as strike throughof the primary backing may occur. It is also important not add thickenerto the base material followed by addition of water as the compositionmay overthicken locally. It is also important not to add thewater/thickener solution too quickly to the Acronal® as this will resultin curdling and an ineffective solution. The amount of AX8281 can rangefrom 10% of the dry weight of S728 up to 40%, for example 20 to 35%.When present, the antibacterial, fire retardant and surfactant may beadded at the end of the mixing cycle after the addition of water andthickener.

Application of the Latex/Precoating Composition to the Primary BackingLayer

The latex/precoating composition can be applied to the primary backingby roller coating, spraying or by foaming. The amount oflatex/precoating used for a 850 g/m² carpet can be up to 100 g/m². Thelatex/precoating composition serves to lock in the fibre on the back ofthe primary, such as a tufted back layer and acts as a barrier,separating the fibrous carpet from the underlying backing. Thepre-coating is suitably heated to drive off sufficient water to providea solid barrier and to allow for possible cross-linking.

The precoating layer has a thickness which is typically quite thin.Suitably the thickness is about 0.005 mm to 0.1 mm when dry. Thethickness is suitably controlled by the use of spray nozzles and spraypressure. The precoating layer is suitably placed directly on andagainst the back surface of the loop or fibre containing primary backingand is applied in an amount to cover completely the loop backs and tolock in loops so that no mountains or valleys are evident. Duringprocessing the copolymers are cured and crosslinked. The resultingprecoated product is very flexible.

Backing Layer

The floor covering may include a backing layer which imparts stabilityand free-laying properties to the floor covering.

Prior to applying the backing layer, it is possible to shear the carpetfibres it desired. Shearing is performed to cut the closed loop, tuftedyarn on the face surface and to provide for the cut, tufted yarn to havethe same general height as the height of the face wear surface fibres.

The backing layer may be formed from one or more layers of athermoplastic polymer or other suitable backing material such asdescribed above for the primary backing. In one embodiment thethermoplastic is a vinyl halide. A suitably vinyl halide is PVC(polyvinylchloride). Other suitable backings include bitumen, atacticpolypropylene, polyolefin, ethylene vinyl acetate copolymer,thermoplastic elastomers, polyurethanes, PVC/Latex, Bitumen backed latexand polyurethane, polyamines, jute, urethane, polyvinylidine chloride,polyvinyl acetate, polyvinyl butyral, natural or synthetic rubber,polychloroprene. The backing layer may be in the form of a foam, spongeor solid. When in the form of a foam, the backing layer adds resilienceand/or stability.

The backing layer can have a range of properties depending on the natureof polymers, plasticizers, stabilizers and fillers used.

Generally about 2.88 kg/m² of PVC is required to make carpet. When usingthe optional precoating composition of the present invention, whilst itis possible to still use 2.88 kg/m², it is desired to reduce the amountof PVC to about 1 kg to 2 kg/m², with 1.5 kg to 1.6 kg/m² beingparticularly suitable and still retain the flexibility. For bitumentiles 2.8 kg/m² of bitumen paste is suitably added.

Backing Composition According to One Embodiment of the Invention

In one embodiment the backing is formed from a composition including afiller and a plasticizer together with a thermoplastic polymer such asPVC. In one embodiment of the invention, there is provided the use ofrecycled glass as filler in a PVC plastisol for the manufacture of acarpet tile. In one embodiment a composition for preparing a floorcovering is used comprising: a thermoplastic resin; a plasticizer whichis a mixture of an epoxidized soybean oil with an acetic acid ester ofcastor oil, and a filler. In another embodiment a composition forpreparing a floor covering is used comprising: a thermoplastic resin; atleast one plasticizer; and recycled glass.

The filler may be limestone or recycled glass or a combination of bothrecycled glass and limestone in any ratio of both. In a particularlypreferred embodiment the filler is recycled glass. As the glass that maybe used has a specific gravity of 2.0 to 2.5 and limestone a specificgravity of 2.7, less volume of glass is required than that of limestone.For example for 1357 kg of PVC paste, about 825 kg of limestone filleris required whereas only 611 kg of recycled glass is required.

The recycled glass fibres suitably have a particle size smaller thansand grains and are prepared by use of a ball mill so that they areround glass particles. They are typically an inert by-product (consumerwaste) and do not absorb any of the plasticizer oil whereas limestonewhen used may absorb about 17 wt % plasticizer oil.

The recycled glass may be Enviro-glass available from Recycled GlassMediums Australia Pty Ltd of 95 Wisemans Ferry Road Somersby NSW 2250,Australia and available in particle size ranges less than 0.106 mm up to10 mm, for example 2.5 mm to 1.5 mm, 1.5 mm to 0.75 mm, 0.75 mm to 0.3mm and 0.3 mm to 0.106 mm.

In one embodiment a 300 μm or less fine is used with preference for afine having a majority of particles of less than 200 microns.

The product may be crushed glass—colourless, blue, mixed amber, mixedgreen, may be odourless, inorganic solid, ground and graded glass havinga melting point above 800° C., a specific gravity of about 2.5 (thisvalue is generic, the measured specific gravity of the product may be 2)and is typically insoluble in water.

The recycled glass may contain soda lime silica glass of the followingchemical composition:

Na₂O + K₂O + Li₂O 12-15% CaO + MgO 10-13% Al₂O₃ 1-2% Other oxides(except SiO₂) 0-1% Bound silica balance (contains no free silica)

About 40 to 70 wt % of the recycled glass may be used with respect tothe total mix of plastisol. Suitably 50 to 61 wt % is used.

The plasticizer may be a standard phthalate plasticizer such as DINP,DEHP, DOP, PEG 100, or PEG 200

A particularly preferred plasticizer is the combination of epoxide soybean oil and a castor oil derivative. In view of the fact that theepoxidised soy bean oil winters (i.e. at low temperatures the oilsolidifies), it is difficult to get the required viscosity andconsequently when used alone, suffers from plastic migration. Epoxidesoy bean oil also does not have a long shelf life. The castor oilderivative results in good viscosity and avoids uptake and migration ofthe soy bean oil. A suitable composition includes 30% castor oil and 70%soybean oil. A suitable range of plasticizer is 40 to 20 wt % castor oiland 60 to 80 wt % soybean oil. A viscosity modifier such as an alcoholmay be present as required to lower viscosity. A suitable viscositymodifier is ethanol. In one embodiment 5 to 10 wt % ethanol may bepresent.

The combination of epoxidised soy bean oil and a castor oil derivativeacts synergistically. Suitably the combination is mixed at roomtemperature.

A suitable soy bean plasticizer is an epoxidised soya bean oil such asLankroflex E2307 (ESBO) AG available from Swift and Company Limited, 372Wellington Road, Mulgrave, Victoria 3170, Australia. Lankroflex E2307 isa low odour epoxy plasticizer containing pure epoxidised soya bean oiland having an oxirane oxygen content of 6.6% min, an iodine value of 2.5max, a viscosity (30° C.) of 350 c-Poise max., an acid value of 0.4 KOHmg/g max., a moisture content of 0.1% max., a specific gravity (25° C.)of 0.992±0.01, a refractive index (25° C.) of 1.470±0.002 and acolour—120 APHA max. Lankroflex E2307 is a clear, yellow, oily liquidhaving a faint fatty odour and is a liquid at normal temperatures. Theproduct has a boiling point above 200° C. at 100 kPa and a flashpoint ofabout 314° C., a specific gravity of 0.99 at 25° C., insoluble in waterand a viscosity of 350 centipoise at 25° C.

The castor oil derivative is suitably an acetic acid ester ofmonoglycerides made from fully hydrogenated castor oil such asGrindsted® Soft-n-Safe/C available from Danisco Emulsifiers. The producthas a degree of acetylation of about 0.9, an iodine value of 4 max, anacid value of 3 max, a saponification value of about 435 and is in theform of a clear liquid. The product contains octadecanoic acid,12-(acetyloxy), bis(acetyloxy)propyl ester (about 85%) and octadecanoicacid, 2,3-bis(acetyloxy)propyl ester (about 10%). The product is aliquid at room temperature and is insoluble in water, decomposes above300° C., and has a flash point above 100° C., a neutral odour, a densityof 1.0030 g/ml at 20° C. and a vapour pressure of 1.05×10⁻⁴ Torr at123.6° C.

A preferred backing layer is formed from a composition comprisingrecycled glass and the soy bean oil/castor oil combination. This resultis a more renewable and less fossil based product. In such a combinationthe composition may include up to about 60% thermoplastic (fossilorigin)

Optional Additives and Layers

The primary backing and backing layer or latex/precoating compositionmay include any one or more of flame or fire retardants, inert fillerssuch as limestone or barytes, calcium oxide, carbon-black,antibacterials, surfactants, defoamers, thickeners, dispersing agents,elastomers, antioxidants, colourants, hardeners, plasticizers, UV/heatstabilizers, viscosity modifiers, cross-linking agents and/ortackifiers.

The use of a plasticizer in combination with the thermoplastic resinprovides the required flexibility, durability and hardness. The presenceof a heat stabilizer stabilizes the thermoplastic and prevents thermaldecomposition, a UV stabilizer stabilizes the thermoplastic preventingdecomposition as a result of exposure to UV light, calcium oxide ensuresany moisture is removed from the mixing process, calcium carbonate(limestone) acts as filler, increasing the volume of the thermoplasticcompound mix at reduced cost and a viscosity modifier maintainsviscosity to ensure that the mix remains well mixed and in suspension(slowing the dropping out of solids).

The floor covering may include one or more woven or non-woven layers ofglass, fibreglass, polyester, Nylon® or polypropylene such as tissue,mesh or fleece or scrim sheet materials or a combination thereof in theprimary backing and backing layer. The scrim material may be employedadjacent to the primary backing or closely adjacent thereto. Glass fibreor tissue materials may be employed within the thermoplastic backinglayer to impart dimensional stability and improve laying properties ofthe carpet tile. Cushion layers for example, formed of foam may also beincluded.

The underside of the backing layer may be provided with an adhesive witha shippable protective layer attached thereto, where, in use theprotective layer is stripped off and the floor covering applied to thefloor surface or applied with a pressure sensitive adhesive.

Application of the Backing Layer and Preparation of the Carpet Tile

The floor covering may be prepared in any suitable manner.

For example, a layer of thermoplastic may be applied/cast in a definedthickness onto the underside of the primary backing layer as a wetplastisol. The coated material is leveled with a doctor blade whichlevels and smooths the thermoplastic layer and forces the thermoplasticlayer into engagement with any glass scrim and the primary backing.

Alternatively, the backing layer may be preformed on a releasablesupport such as a fluorocarbon, glass fibre endless belt, Teflon® coatedfibreglass belt or stainless steel support sheet through casting. Theprecoated primary backing layer is then laid into the liquid backinglayer.

Following application of the backing layer, the carpet is suitablyheated to fuse/gel and cure the thermoplastic, cooled and optionally cutinto carpet tile sections. Heating may be by use of a heater, radiantpanels or heating elements. The heating cures the thermoplastic materialand for a tufted carpet, thereby locks back stitches in place, theprimary backing is thereby bonded to the backing layer by fibres of theprimary backing being embedded in the backing layer. The carpet tile maybe heated to a curing temperature within the range of 50° C. to 170° C.,for example 90° C. to 160° C., 100° C. to 150° C. or 140° C. to 150° C.For example for PVC, the plasticizer melts and begins diffusing intoparticles at 50° C., gelation begins at about 50° C. and continues toabout 130° C., at which point the particles swell, between 130° C. and170° C. the gelation stage ends. At 91° C. the polymer flows into acontinuous mass.

A suitable apparatus for finishing the carpet tile may be an apparatusincluding a heater having a chamber to operate at a desired temperatureand through which the primary backing and backing layers pass to beheated to provide for plastic deformation of the backing layer, a pairof press rollers to which the primary backing, backing and anyadditional cushion layers are delivered, after the primary and backinglayers have been heated by the heater, to apply a force thereto to causethe layers to bond, and a controller operatively associated with theheater, the controller being configured to maintain the temperaturewithin the chamber to provide for heating of the backing layer so thatthe backing layer is relatively deformed by the rollers to bond thelayers.

During gelling or after gelling the carpet may be passed under anembossing roller which embosses the back of the carpet withindentations, corrugations or the like to form a friction-increasingsurface (resisting movement and maintaining position when placed insitu) and assists in consolidating the layers into a unitary product.The consolidated carpet material may then be severed by suitable cuttingmeans into appropriate length sections (for example into squares). Thelaminated construction may be cooled for example to about 105° C. toallow removal of the construction from the support. The construction maythen be passed through a heater and raised to about 100° C. prior tobeing engaged by an embossing roller that embosses the thermoplasticlayer.

In one embodiment, the backing layer is formed of a layer ofthermoplastic such as PVC, a fibreglass scrim and a second thermoplasticlayer such as PVC. The first layer of thermoplastic bonds the primarybacking to the fibreglass layer, the thickness of the layer suitablybeing controlled by a doctor blade. The fibreglass layer is to ensuredimensional stability of the carpet tile. The second layer ofthermoplastic glues the layers above it and provides the final backingof the carpet tile. The thickness of this layer is also suitablycontrolled by a doctor blade.

The backing layer may be applied to the primary backing in a continuousfashion to produce an indeterminate length of material which may besubsequently cut as desired to form the carpet tile.

The thickness of each layer may vary depending on whether a solid layeror foam layer is used. For example, the first PVC layer range isdependant on the weight of the PVC backing i.e., 2.64 kg/m² would be twolayers of 0.88 mm, 2 kg/m² would be two layers at 0.67 mm, while 1.5kg/m² would be two layers at 0.5 mm. The overall carpet thickness maysuitably be between about 4 and 12 mm, for example about 6 mm withoutfoam backing and about 10 mm with foam backing.

Application

The resulting floor covering is suitable for use as a floor covering inhome and/or commercial use. Pressure Sensitive adhesives may be requiredfor installation and where floor tiles are prepared, the floor tiles canbe replaced or rotated as desired. The floor covering has dimensionalstability with substantially no curling, slipping, buckling, stretchingor shrinkage and a low smoke emission. The floor covering is also stainresistant having a stain factor of 5 compared to previous nylons whichhave a stain factor of 2.

EXAMPLES Example 1

Ultramid Balance® biobased nylon 6,10 resin available from BASF wasdried, melt spun, drawn and air-jet textured to produce bulkedcontinuous filament yarns of 1000 denier containing 60 filaments oftri-lobe cross-section. Four coloured yarns were produced via theaddition during the melt spinning stage of formulated masterbatchescontaining various pigments. The four colours were dark brown(“Raisin”), light grey (“Hawk Grey”), medium grey (“Elephant”) and darkgrey (“Seal”). The spin speed was 1100 m/min with a draw ratio of about2.7:1. Finish oil was applied to the yarn during the spinning stage togive about 0.45% wt finish on yarn. The tenacities and elongations tobreak of the four yarns produced were as follows:

Tenacity/ % Elongation Yarn Colour g/denier at break Raisin 3.19 76 HawkGrey 3.18 81 Elephant 3.15 73 Seal 3.04 73

Example 2

A yarn comprising 90% wt of the 6,10 resin used in Example 1 and 10% ofa nylon 6,6 resin with a sulfuric acid relative solution viscosity of3.1 was produced using a similar process to Example 1. The nylon 6,10and the nylon 6,6 were melt blended during the melt spinning stage. Thebulked continuous yarn produced had a denier of 600 and consisted of 30filaments of a tri-lobe cross-section.

Example 3

Carpet Tiles were prepared using the yarns prepared in Example 1 and 2.The resulting carpet tiles were found to pass the following propertytests: Colourfastness, Tuflock, Lisson, Castor Chair, DimensionalStability, Hexapod and Critical Heat Flux.

While the invention has been described with respect to a preferredembodiment, it will be understood that the invention is not limited tothe preferred embodiment but is intended to cover various modificationsand equivalent arrangements within the spirit and scope of the appendedclaims.

What is claimed is:
 1. A floor covering including a primary backinglayer having a fibrous face and an underside, wherein the fibrous faceis formed from a bulked continuous filament yarn comprising a pluralityof continuous filaments formed from a multi-component fibre comprising abiobased polyhexamethylene sebacamide polymer or a blend of a biobasedpolyhexamethylene sebacamide polymer together with up to 80 wt % of atleast one other polymer compatible with the biobased polyhexamethylenesebacamide polymer.
 2. A method of making a floor covering comprisingthe step of tufting or implanting a bulked continuous filament yarn intoa primary backing material, wherein the yarn comprises a plurality ofcontinuous filaments formed from a biobased polyhexamethylene sebacamidepolymer or a blend of a biobased polyhexamethylene sebacamide polymertogether with up to 80 wt % of at least one other polymer compatiblewith the biobased polyhexamethylene sebacamide polymer.
 3. The floorcovering of claim 1 further comprising: a cured precoat layer on theunderside of the primary backing; and a backing layer fixed to theprimary backing.
 4. The method of claim 2 wherein the yarn comprises aplurality of continuous filaments formed from a multi-component fibrecomprising a biobased polyhexamethylene sebacamide polymer or a blend ofa biobased polyhexamethylene sebacamide polymer together with up to 80wt % of at least one other polymer compatible with the biobasedpolyhexamethylene sebacamide polymer; and wherein the method furthercomprises the steps of precoating the underside of the primary backinglayer by applying a precoating composition; applying a backing layer tothe precoated primary backing layer; and curing the precoatingcomposition.
 5. The method of claim 2 wherein the yarn comprises aplurality of continuous filaments formed from a multi-component fibrecomprising a biobased polyhexamethylene sebacamide polymer or a blend ofa biobased polyhexamethylene sebacamide polymer together with up to 80wt % of at least one other polymer compatible with the biobasedpolyhexamethylene sebacamide polymer; and wherein the method furthercomprises the steps of: coating a first layer of a thermoplastic resinplastisol on a support surface; optionally placing a dimensionallystable sheet material onto the top surface of the first layer andheating the layer to gel the layer and position the sheet material;optionally applying a second layer of a thermoplastic resin plastisolonto the gelled surface of the first layer; precoating the underside ofthe primary backing; optionally coating a thermoplastic resin plastisolover the precoat layer; layering the precoated primary backing onto thetop surface of the plastisol of the first or second thermoplastic resinlayer; heating the floor covering so formed to fuse the thermoplasticlayers into an integrally-fused backing layer; cooling the flooringcovering; and optionally cutting the floor covering into a carpet tile.6. A floor covering produced by the method of claim
 2. 7. A floorcovering produced by the method of claim
 4. 8. A floor covering producedby the method of claim 5.